Sole for Footwear, for Postural and Balance Training

ABSTRACT

A sole for footwear, which includes a plurality of separate closed fluid filled sacs, flexibly secured together and arranged with said sacs extending across the full extent of convexities of the primary weight bearing surfaces of the wearer&#39;s foot said sacs include: at least one sac under the wearer&#39;s heel; at least five sacs lie under the rest of the wearer&#39;s foot; said sacs being arranged such that no part of any of the sacs lies under the medial longitudinal arch of the wearer&#39;s foot; wherein said at least five sacs include: one sac which lies under the medial forefoot of the wearer&#39;s foot; one sac which lies under the lateral forefoot of the wearer&#39;s foot; one sac which lies under the lateral midfoot of the wearer&#39;s foot; one sac lies under the big toe of the wearer&#39;s foot; one sac lies under the smaller toes of the wearer&#39;s foot.

TECHNICAL FIELD

The present invention relates to a sole for footwear for improving the posture and balance of the wearer.

BACKGROUND ART

Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of the common general knowledge in the field.

Problems with abnormalities or irregularities of posture may be treated by providing the patient with footwear insoles which provide a specially shaped and/or cushioned surface on which the foot can rest. These insoles are designed to passively compensate and/or accommodate for postural problems. Although in some cases these insoles provide little relief, in many cases insoles provide considerable relief of posture-related alignments. However, they achieve this by the application of passively acting forces, in that they do not instigate conscious active involvement by the wearer to change body posture. Supportive insoles force the base of the foot to conform to the shape of the insole. Subsequent postural changes are transferred from this source through the ankle and up the leg. Cushioned insoles are commonly made of gel substances which act to spread load forces at sites of high plantar pressure. These insoles do not teach the wearer how to correct their related postural problems; they simply treat the results of those postural problems. In most cases the user is dependent upon the ongoing use of the insoles.

When the foot is in contact with the floor, its posture is principally regulated by the orientation of body load with respect to the area of contact. This orientation provides a reference of body balance with respect to the foot. The orientation of body load is determined by the way in which body segments are arranged in relation to each other. The most relevant segments to foot postures are the lower limbs, pelvis, waist and chest. The latter three are centrally located and have large masses. The latter two are inclusive of the lumbar and thoracic spines respectively. This segmental arrangement facilitates significant changes in foot related forces in response to small interrelated changes in body segment positioning. The effectiveness of this mechanism is enhanced by the general flexibility of these body segments, which allows for multi-direction movements both between and within the segments.

This highly effective body load to foot posture relationship is further enhanced by the incorporation of loads obtained from the neck, head and upper limb body segments. In general terms, foot posture and related body balance, can be referenced to the interrelated stacking of principally centrally located body segments, over the respective lower limb and foot. The remaining segments contribute in an integral manner to body posturing and balancing but this contribution is more specialised and directed toward the achievement of functional tasks, such as eye-hand related tasks. In relation to body balance, the laterally located upper limbs contribute dynamic refinement to the balancing task.

The foot is capable of multi-positional and multi-directional foot sole to floor interactions. The most fundamental of these can be reliably qualified by the manner in which the primary weight bearing sites of the foot sole interact with the floor. The sole of the foot has a wealth of neural sensors which have the potential to provide accurate sensory information concerning this interaction. With training, this information can be readily utilised to assess the quality of the fundamental foot postures and predisposing body segment orientations. With ongoing training, the quality of body postures can be assessed in relation to any multi-positional and multi-directional foot sole to floor interaction.

The primary structural components of the foot are its three arches:—the medial longitudinal arch, the transverse arch, and the lateral longitudinal arch. They provide the foot with a structurally interdependent triangular framework of arches. Correct foot posture is dependent upon the correct formation of all three arches. This applies to all variations of contact between the foot sole and floor. The three primary foundations of these arches coincide with the three primary weight bearing sites on the foot sole. These are the heel, medial forefoot and lateral forefoot. The quality of foot to floor interaction of one or more of these sites is directly related to the quality of formation of all three arches. In addition, the structural integrity of the foot ensures that the three arches are correctly formed when any one or more of the primary weight bearing sites is correctly loaded. The sensors located under these sites readily provide this information.

As used herein:

-   -   the term “medial forefoot” refers to the sole foot pad of the         first metatarsal head;     -   the term “lateral forefoot” refers to the sole foot pad of the         second to fifth metatarsal heads;     -   the term “lateral midfoot” refers to the sole foot pad of the         cuboid and the bases of the third, fourth and fifth metatarsals.

Correct and incorrect foot and body postures can be correlated with respect to the systemic alignments of joints. Joint alignment is a systemically interdependent phenomenon, in that the forces responsible for a correct or incorrect posture act to respectively align or misalign all involved joints. It is not uncommon for some joints to be incapable of correctly aligning in response to correct posture joint forces, and thereby, remain to some extent misaligned; this usually applies to joints with some extent of chronic damage. When joints are aligned they have minimal friction, multidirectional movement capabilities. When misaligned, the movements of all involved joints are in some way restricted. In summary, correct foot posture, for any given interaction between the foot sole and the floor, is dependent upon a corresponding correct general body posture, which is a construct of systemically aligned joints. The most applicable joints are those most contributory to the body posture, in particular, those of the lower limb, pelvis and lower spine.

The correct training of body balance is dependent upon the training of predisposing correct body postures. The beginning of this training involves learning to correctly balance the body over one or more of the primary weight bearing sites of the foot sole. These sites are identified on the sole of the foot as convex shaped pads of skin, whose weight-bearing surface extends across the full extent of their convexity. They are the heel, lateral midfoot, medial forefoot, lateral forefoot, big toe and the small toes. Of the small toes, the smallest toe is the most relevant to foot posture and balance. These sites are the primary weight bearing foundations of the dynamic foot structure. The medial longitudinal arch of the foot sole is not a correct weight bearing surface. It is contoured by the weight bearing surfaces of the heel, lateral midfoot, lateral forefoot and medial forefoot, of the foot sole.

The sensory input obtained from the loading of the primary weight bearing sites provides the wearer with an awareness of how the foot sole contacts the floor for static and dynamic foot function. This information can be assessed by the wearer to determine the quality of fundamental foot function, and the interdependent quality of systemic lower limb joint alignments. This integral correlation between foot loading and lower limb joint alignments, also applies to the alignments of joints of the pelvis and to some extent those of the spine. This assessment is determined by the ability of the wearer to balance their body over one or more of these foundation sites.

The state of being evenly/well balanced over one or more of these sites is indicative of correct systemic alignment of joints of these body parts. Correct joint alignment applies to the maximal area of contact between opposing joint surfaces for any given joint position. This principle feature of correct alignment can be similarly referenced to the maximal area of contact between the primary weight bearing sites of the foot and the floor. This applies to any given static posture or dynamic body movement. When joints are correctly aligned their joint surfaces are best coupled. This facilitates the least wear of joint surfaces in addition to minimal friction movements of coupled surfaces. Accordingly, the correct systemic alignment of joints facilitates best quality multidimensional body movements; and this is most applicable to the multidimensional dynamics of body balance.

In summary, the foot is capable of multi-positional and multi-directional foot sole to floor interactions and the quality of these interactions can be referenced to the quality of whole body postures.

The achievement of high quality whole body postures requires advanced training. The starting point of this learning process is familiarisation with the fundamental weight bearing components of the foot which are the primary weight bearing sites of the foot. This familiarisation can be referenced to the quality of foot postures and respective quality of body postures. The indications of high quality function are the maximal spread of foot sole to floor contact and mutual state of body balance, over one or more of the primary weight bearing sites. High quality function applies to the systemic correct alignments of joints of the lower limbs, pelvis and to some extent the spine. This starting point of learning advances to being able to attain a high quality of body function for all static postures and dynamic movements of the body, with respect to the fundamental weight bearing components/sites of the foot.

Maximal contact between the foundation sites of the foot sole and the floor facilitates the optimal input of sensory information from the foot sole to the brain. Minute disturbances in correct foot posture and integral balance relationships are readily detected by the brain, which responsively instigates corrective body manoeuvres. This initial learning process is essential to attain a high level of function for all applicable foot sole to floor interactions. Awareness of foot positioning and balance is provided by foot sole senses.

Prior patent number PCT/IB2010/054855 discloses an invention (“the prior invention”) for correcting the wearer's posture by providing an article of footwear the underside of which carries a continuous line of fluid filled sacs which are aligned along the length of the sole; each sac extends across the full width of the weight bearing portion of the sole. Because of this, the prior invention takes into account only a midline or neutral position of the foot for training purposes and thus does not assist the wearer to become familiar with a multi-postured foot for multi-positional and multidirectional orientations with respect to the floor.

In contrast, the present invention has medial and lateral located sacs for the forefoot and for the toes regions:—this teaches the wearer to become familiar with a multi-postured foot.

The teaching of normal healthy foot function, and integral correct body posture and balance, is reliant upon the wearer becoming familiar with all the primary weight bearing sites of the foot, and the boundaries of movements of these sites. The present invention accurately achieves this task by having sacs that are respectively shaped and positioned under each of these sites. In particular, the incorporation of medial and lateral positioned sacs for the forefoot and toes teaches the wearer to transfer weight bearing in different directions; this can be to one or more particular weight bearing sites or multi-directional movements between different sites. The outer boundaries of each primary weight bearing site are indicated to the wearer by the tilting of respective sac or sacs and associated rolling movements of the foot. Familiarisation of these boundaries is essential for teaching correct foot posture and body balance. The prior patent is counterproductive in this regard as it does not have separate sacs for each primary weight bearing site. It has sacs that extend across the entire width of the weight bearing portions of the forefoot and toes. As a result the wearer is not familiarised with the individual weight bearing sites and their essential contribution to foot function.

The correct formation of the three foot arches for regular foot function is dependent upon the wearer learning to isolate weight bearing to the foundation sites of the arches. The primary sites are the medial and lateral forefoot, and the heel. The medial and lateral toes respectively contribute to these structural foundation sites. The wearer must be able to correctly weight bear upon each of these sites for the correct formation of the three arches. The prior patent does not provide for this learning as it does not have appropriately positioned sacs.

Body balance necessitates subtle multidirectional foot and associated body movements. For training purposes these skills need to be learnt in a manner that is safe and accordingly reassuring for the student. The present invention footwear provides this method of learning as it has a spread of sacs that readily detect all directions of foot movements, and this information is obtained from subtle changes in sac shape. The prior patent footwear is counterproductive as its arrangement of sacs does not detect medial and lateral deviations of the foot. It has sacs that extend across the entire width of the weight bearing portion of the foot. To remain balanced the wearer must centre their weight bearing directly over the respective sac. Medial and lateral deviations of the foot cause the respective sac to significantly wedge and the foot to quickly roll. These dramatic movements predispose the wearer to lose their balance, with the likelihood of a fall. As a result, the wearer learns to avoid the medial and lateral weight bearing sites of the foot, rather than become familiar with them and their integral role for maintaining body balance.

Correct heel weight bearing is dependent upon the wearer becoming familiar with all primary weight bearing sites. Both the prior patent footwear and the sole of the present invention have one or two sacs positioned under the heel, but in isolation they contribute little to correct foot function. Apart from the split second duration of heel strike for gait, the isolated use of the heel for foot function is very rare. This is because it requires exceptional balance skills to balance one's body over the heel and accordingly, this is an unrealistic learning task for the vast majority of people. Correct balancing of the body over the foot requires medially and laterally located forefoot and toe sacs, in addition to one or two heel sacs. The lateral midfoot sac also contributes to this role but in a less significant manner.

In combination, the medial forefoot, lateral forefoot and heel, construct a triangular shaped stable platform upon which the body can balance. This triangular platform is made robust by the correct formation of the corresponding three foot arches and further enhanced by the medial and lateral toes. Subtle deviations in body balance are readily detected by changes in the loading of respective sacs and their triangular arrangement. Learning correct heel function is therefore dependent upon the integral learning of whole foot function. The basis of this learning is familiarisation with all primary weight bearing sites. The prior patent is therefore incapable teaching correct heel function even though it has specific heel sacs. In particular, the prior patent footwear does not familiarise the wearer with the most important of foot positions, which is the position used for stable regular standing, as it does not familiarise the wearer with the stable triangular arrangement of the primary weight bearing sites.

The prior patent footwear has a single toe sac positioned across the full width of the weight bearing portion of the toes. This sac arrangement prioritises one site and one direction of toe-off for gait. Normal foot function for gait involves multi-positional sites of toe-off in accordance with multidirectional body movements. The present invention accommodates this learning by having medial and lateral positioned toe sacs. The (optional) incorporation of three sacs under the toes further enhances the sensory information obtained from the toes, to further enhance the toe-off related learning process. The prior patent is counterproductive in this regard as deviations in toe-off from the dictated toe off site, would cause its single toe sac to significantly wedge and the weight bearing toes to drop. The wearer's foot would accordingly tilt and this would discourage the wearer from learning multidirectional toe-offs, as they provided unstable platforms for toe weight bearing. Most importantly, the prior patent fails to teach the most important site of toe-off, which is the big toe site, as it lacks a separate big toe sac. The big toe is by far the strongest of the toes and provides the foot with a very robust and powerful toe-off site. This capability is especially important for jumping, sprinting and standing on one's toes.

Normal foot function necessitates the molding of the foot in accordance with foot movements and ground contours. The prior patent is counterproductive at teaching correct foot molding as it promotes a stiffening of the foot to maintain a single midline posture. The present invention is designed to teach the correct molding of the foot in relation to differing foot weight bearing, differing directions of body travel and differing ground contour.

DISCLOSURE OF INVENTION

An object of the present invention is the provision of a sole for footwear which teaches the wearer to balance his or her body over one or more of the primary weight bearing sites of the foot. The same learning process attains the interdependent correct systemic alignment of lower limb, pelvis and spine joints. This applies to static body postures and dynamic body movement postures. The present invention is intended to teach the wearer to attain correct body postures for the most fundamental of foot-sole-to-floor interactions. These apply to the attainment of correct body postures when the body is correctly balanced over one or more of the primary weight bearing surfaces of the foot sole. The body is capable of attaining correct body postures for many variations of foot sole to floor contact, but these demand an advanced level of whole body awareness and control. This advanced level of control is considered to be dependent on the learning of correct fundamental body postures. Accordingly, the skills learned from use of the present inventions can facilitate the ongoing learning of more advanced posture skills.

The present invention provides a sole for footwear, said sole including a plurality of separate closed fluid filled sacs, said sacs being flexibly secured together and arranged such that said sacs extend across the full extent of convexities of the primary weight bearing surfaces of the wearer's foot in use; said sacs include:

-   -   at least one sac lies under the wearer's heel in use;     -   at least five sacs lie under the rest of the wearer's foot in         use;     -   said sacs being arranged such that no part of any of the sacs         lies under the medial longitudinal arch of the wearer's foot in         use;     -   wherein said at least five sacs include:     -   one sac which lies under the medial forefoot of the wearer's         foot in use;     -   one sac which lies under the lateral forefoot of the wearer's         foot in use;     -   one sac which lies under the lateral midfoot of the wearer's         foot in use;     -   one sac lies under the big toe of the wearer's foot in use;     -   one sac lies under the smaller toes of the wearer's foot in use.

Preferably, the sac which lies under the wearer's heel in use is sub-divided into two separate independent sacs, one of which lies under the outer heel and the other of which lies under the inner heel.

Preferably, the sac which lies under the smaller toes of the wearer's foot in use is sub-divided into two separate independent sacs, one of which lies under the smallest toe and the other of which lies under the remaining smaller toes.

The sole of the present invention may be provided as an insole for an existing article footwear, or may be built into the lower (i.e. ground contacting) sole of an article of footwear.

Both versions of the present invention are designed to be positioned under the sole of the foot and have components that correlate in position and shape with the primary weight bearing sites of the foot sole.

In the case of a sole which is designed to be worn as an insole i.e. inside an article of footwear, each of the sacs preferably is substantially oval in cross-section.

In the case of a sole which is designed to be worn on the lower sole of an article of footwear, preferably each of the sacs is substantially spherical in cross-section.

Both versions provide the wearer with instant sensory information concerning their whole body positioning with respect to the footwear and the floor. This sensory information includes the spread of surface area contact over one or more of the primary weight bearing sites of the foot sole. It mutually includes the wearer's state of balance or imbalance over one or more of the components of the footwear. The states of surface area spread and balance are governed by the whole body positioning of the wearer. This whole body positioning particularly applies to central body segments due to their increased mass. Maximal surface area spread and mutual balance inform the wearer of correct body postures. Less than maximal surface area spread and mutual imbalance inform the wearer of incorrect body postures.

The body forces responsible for incorrect body postures are to some extent damaging to all involved joints and corresponding tissues. The significant improvements in foot and respective body postures obtained from the footwear training, significantly lessens these damaging forces. When pain is a consequence of these forces, this lessening often resolves the pain.

The significant improvements in body balance obtained from the training facilitates a significantly reduced likelihood of falls. This is particularly relevant to the older generation.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, preferred embodiments of both versions of the present invention are described in detail with reference to the accompanying drawings in which:

FIG. 1 a is a side view of a preferred embodiment of an insole in accordance with the present invention, showing the lateral aspect of the insole before a wearer applies weight to the insole;

FIG. 1 b is a side view of a preferred embodiment of an insole in accordance with the present invention, showing the medial aspect of the insole positioned within a lengthwise vertically sectioned shoe, before a wearer applies weight to the base of the shoe;

FIG. 2 a is a plan view of a preferred embodiment of an insole in accordance with the present invention, showing the underside of a right insole. It conversely also shows the topside of the left insole due to the reciprocal structure of the insole;

FIG. 2 b is a three dimensional medial view of a preferred embodiment of an insole in accordance with the present invention, showing a variant formation of the insole. This variant formation is shaped to conform to the shape of the foot sole in a similar manner to a regular shoe insole.

FIG. 3 is a plan view of a midline horizontal section of the underside of a right insole through the line A-A of FIG. 1A; It conversely also depicts the topside view of the same section of the left insole due to the reciprocal structure of the insole.

FIG. 4 is a side view of a vertical section of the medial aspect of the insole through the line C-C of FIG. 3 . It also depicts three dimensional images of the same section through sacs 13 i and 15 i;

FIG. 5 is a horizontal sectional side view of the medial aspect of the insole through the line D-D of FIG. 2A, within a lengthwise vertically sectioned shoe, after the wearer applies weight to the insole;

FIGS. 6 a-e are vertical sectional views of the insole and wearer's forefoot through the line B-B of FIG. 2 a , under a series of different conditions in use;

FIG. 7 is a sectional side view of the medial aspect of the insole through the line D-D of a variant form of the insole as depicted in FIG. 2 b . As for FIG. 2 b the shape of the insole more closely conforms to the shape of a regular insole.

FIG. 8 a is a side view of the preferred embodiment of a shoe fitted with a sole in accordance with the present invention, showing the medial aspect of the shoe before a wearer applies weight to the base of the shoe;

FIG. 8 b is a side view of a preferred embodiment of a shoe fitted with a sole in accordance with the present invention, showing the lateral aspect of the shoe before a wearer applies weight to the base of the shoe;

FIG. 8 c is a side view as in FIG. 8 a , but showing the compression of sacs after a wearer applies weight to the base of the shoe;

FIG. 9 is a plan view of a preferred embodiment of a shoe fitted with a sole in accordance with the present invention, showing the underside of the shoe;

FIG. 10 is a plan view of the underside of the shoe showing a horizontal sectional view of the sacs through the line G-G of FIGS. 8 a/b/c;

FIG. 11 is a vertical sectional view of the lateral aspect of the shoe through the line F-F of FIGS. 9 and 10 ;

FIG. 12 is an exploded view version of FIG. 11 ;

FIG. 13 is a sectional side view as in FIG. 11 but with the wearer applying weight to the base of the shoe;

FIG. 14 a-e are vertical sectional views of the shoe on the line E-E of FIG. 8 a , under a series of different conditions of use;

FIG. 15 is a plan view of a variant form of an insole in accordance with the present invention; and

FIG. 16 is a plan view of the underside of a shoe fitted with a variant of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Referring to FIG. 1-7 of the drawings, a first embodiment of the present invention is depicted in the form of an insole 20 i which consists of a series of fluid filled sacs 12 i to 19 i inclusive. The series of sacs are embedded within a layer of material 21 i that binds the sacs together. The insole (20 i) can be shaped in the form of a flat insole or in the form of a regular shoe insole.

The insole 20 i must be sufficiently pliable to remain comfortable while conforming to the shape of the wearer's foot.

The insole 20 i may be made of any of a large range of suitable robust and flexible materials, e.g. rubbers or plastics such as polyvinyl chloride, foam, felt, neoprene and leather.

As shown in FIGS. 2 a, 2 b and 4, the sacs 12 i to 19 i are consistent in thickness but vary in size, shape, contour and position in accordance with the respective primary weight bearing sites of the underside of the foot.

FIGS. 6 a,b,c,d and e show vertical sections of the insole 20 i and the forefoot 22, through the line B-B in FIG. 2 a.

As used therein, the term “medial” refers to the inner side of the shoe i.e. the side closest to the opposite shoe. The term “lateral refers to the outside of the shoe i.e. the side furthest from the opposite shoe.

Referring to FIG. 8-14 of the drawings, an article of footwear in accordance with a second embodiment of the present invention is depicted in the form of a shoe 10 which is provided with an upper 11, and a series of fluid filled sacs 12 s-19 s inclusive secured to or built into the sole.

The upper 11 must give support to, and fit firmly around the foot of the wearer, but must also be sufficiently pliable to remain comfortable while conforming to the shape of the wearer's foot. The upper 11 may be made of any of a large range of suitable materials, for example lightweight canvas or thin leather, secured by laces or hooks or velcro tabs; or an elasticated material sufficiently tight-fitting to give good support. The sacs may be made of any suitable, robust, flexible material, e.g rubber or plastics such as polyvinyl chloride.

The unified structure of sacs—20 s—is permanently secured to the underside of the upper, e.g. by welding or gluing or may be formed integrally with the upper.

FIG. 14 a shows a sectional view through sacs 15 s and 16 s in an unloaded state. Sac 16 s is the medial forefoot sac. Sac 15 s is the lateral forefoot sac. In this figure they are spherical in shape and designed to behave like moderately firmly inflated balls when balanced upon. As such they function as multidirectional balance platforms. The upper and lower surfaces of the sacs are convex in shape. The lower surfaces of the sacs are depicted to have a slight V shape incorporated into their convexity, however their shaping could be the same convexity as the upper surfaces of the sacs. A slight V shape increases the steepness of their rocker and thereby the instability of sacs when loaded. In general terms the shape of each sac can be described as a slightly oval ball. Accordingly, when compressed and rolled, the rocker actions of each sac can be likened to that of a moderately firmly inflated oval shaped ball, which is multidirectional.

Typical heights of sacs, (unweighted) measured from upper to lower surface are 20-60 mm depending upon the age and weight of the wearer.

In both versions of the invention:—

-   -   1. The sacs are sealed, and do not leak the fluid contained         therein. Fluid cannot pass from one sac to another.     -   2. The sacs are capable of molding appropriately in relation to         loading by the wearer. This may be achieved by providing that         the fluid is free to move from one portion of a sac to another         portion when the wearer's weight is applied. The sacs may be         filled with any suitable fluid, e.g. air or liquid at ambient         pressure, or air or liquid at above ambient pressure.     -   3. The sacs in total provide support only for the weight-bearing         parts of the foot, and do not underlie the medial longitudinal         arch of the foot when in use.     -   4. Each sac must be correctly positioned under the corresponding         primary weight bearing site of the foot for correct balance to         be achieved by the wearer. This extends from the rear-most         curved part of the heel to the front-most curved parts of the         toes. These curved parts of the heel and toes accommodate heel         strike and toe off respectively. The curved surfaces of the feet         naturally facilitate rolling foot movements and generally         improve the smoothness and energy efficiency of regular gait.         For the shoe, the balanced loading of sac 12 s instructs the         wearer of the correct location on the heel for heel strike. For         the insole, the balanced loading of sac 12 i instructs the         wearer of the correct location on the heel for heel strike. The         incorporation of three separated toe sacs for the shoe (17 s, 18         s and 19 s) and insole (17 i, 18 i, and 19 i) accommodates         different sites of toe off in relation to predisposing body         direction movements. The most important toe off site is the big         toe and this is accommodated by the big toe sac 19 s for the         shoe, and 19 i for the insole.

Each sac is permanently attached to one, two, three or four other sacs depending upon their position within the unified sac structure (20 s or 20 i). Each sac is sealed so there is no passage of fluid between each sac. The attachment between each sac is of a flexible material that permits each sac to bend in relation to its neighbour, and thus the unified structure of sacs (20 s and 20 i) is a flexible entity.

Each sac is of sufficient robustness to withstanding the entire weight of the wearer. The extent of sac compression would be in relation to the applied load. Sac stability alters in relation to the orientation of the applied load:—the further the applied load lies from the centre of the sac, the more unstable the sac.

FIGS. 6 b and 14 b show sectional views similar to those of 6 a and 14 a respectively, but in the circumstances where the forefoot is loaded:—this load is spread evenly across sacs 16 i and 15 i for the insole, and sacs 16 s and 15 s for the shoe, and both respective sacs operate as multidirectional balance platforms.

As shown in FIGS. 6 c and 14 c , when the load on the sacs shifts medially, sac 16 i for the insole and sac 16 s for the shoe, have an increased load, and sac 15 i for the insole and sac 15 s for the shoe, a decreased load. Both shoe and insole sacs still act as multidirectional balance platforms, but sacs 16 i and 16 s are now the primary loaded sacs and the primary multidirectional balance platforms.

FIGS. 6 d and 14 d illustrate the circumstances where the load has shifted slightly further medially, compared to FIGS. 6 c and 14 c respectively. For these figures, sacs 16 i and 16 s have further increased load, and sacs 15 i and 15 s have a further decreased load. In this configuration, sacs 16 i and 16 s are evenly loaded and function solely as the multidirectional balance platforms.

FIGS. 6 e and 14 e illustrate the configurations where the load is shifted slightly further medially compared to FIGS. 6 d and 14 d respectively. In these configurations body load forces are no longer balanced on sacs 16 i and 16 s, causing the sacs and the forefoot to roll medially. Sacs 16 i and 16 s now act as unidirectional unbalanced platforms rather than multidirectional balance platforms. This unbalancing rolling force is more pronounced for the shoe version than for the insole version due to the rounded shape and increased size of the shoe sacs. In comparison the insole sacs are flatter and thinner in shape and accordingly act to slightly tilt the wearers foot when unevenly loaded, rather than significantly rolling it. The tip response of the insole sacs is principally intended to inform the wearer of sac imbalance and corresponding incorrect body posture, rather than actually unbalancing the wearer.

It should be emphasized that neither the shoe nor the insole version is intended for normal use:—they are specifically for retraining the deportment of the wearer so as to offer a significant correction of postural problems and balance improvements. The present invention is intended to be used for short periods only. In particular, the shoe version is not recommended for regular wear as the unstable features of the shoe may predispose the wearer to injury, including a fall. The shoe version is not designed to provide significant traction with the ground. For this reason the shoe version should only be worn on non-slip and flat indoor surfaces. Neither version is particularly designed to be durable for everyday activities.

The incorporation of distinct medially and laterally located forefoot and toe sacs 15 i, 16 i, 17 i, 18 i and 19 i for the insole and 15 s,16 s,17 s, 18 s and 19 s for the shoe, into the designs of the footwear is essential to teach correct foot and corresponding body postures; in addition to body balance. Without this inclusion the wearer would not be able to identify the primary medial and lateral weight bearing sites and how to correctly balance his or her body load over them individually, or between them transversely and diagonally. A training exercise that involves these movements is for the wearer to consider the majority balanced loading of any sac to be a barrier to further transverse or diagonal movements. This exercise trains the wearer to skillfully maintain a stable foot for balance training.

The three foot arches are the medial longitudinal arch, the transverse arch and the lateral longitudinal arch. The footwear and insole inventions are designed to teach the wearer to become familiar with their correct formation and function. The primary foundations of the medial longitudinal arch are accommodated by the inner heel sacs (sacs 13 i and 13 s) and the medial forefoot sacs (sacs 161 and 16 s). The primary foundations of the transverse arch are accommodated by the medial forefoot sacs (sac 161 and 16 s) and the lateral forefoot sacs (sac 15 i and 15 s). The primary foundations of the lateral longitudinal arch are accommodated by the lateral forefoot sacs (sacs 15 i and 15 s) and inner heel sacs (sacs 13 i and 3 s). The balancing of body load over one or more of these sacs correctly forms all three arches. This also applies to the balancing of body load over one or more of the remaining sacs due to the correlation between correct primary site weight bearing and the correct formation of all three foot arches. Subtle foot movements between sacs 13 i, 15 i and 16 i for the insole or sacs 13 s, 15 s and 16 s for the shoe, can be interpreted to replicate the coursing of arch spans of three arched bridges, from foundation to foundation, that are arranged in the shape of a triangle. The smaller toe sacs (17 i, 18 i or 17 s, 18 s) and big toe sacs (sac 19 i or 19 s) act as important outer sensors to inform the wearer of the correct respective medial and lateral outer limits of the transverse arch. In summary, without the incorporations of medial and laterally located sacs into the designs of the footwear, they would not be able to teach the wearer the outer limits of correct foot postures for fundamental foot postures. The wearer would accordingly not become familiar with the form of the three foot arches. As such, the wearer would not become familiar with the inter-relationships of foot postures, body postures and body balance, which are based upon the correct formation of the three foundation arches. Without this basic knowledge the learning of more advanced body postures and balance skills would not be facilitated.

The outer heel sacs (12 i and 12 s) also contribute to heel weight bearing, but are separated from the inner heel sacs (13 i, 13 s) to provide the wearer with improved perceptions of weight bearing across the length of the heel. An improved perception of the back region of the heel (supported by the sacs 12 i/12 s) better informs the wearer of the correct location for heel strike and facilitates improved body positioning and balancing with respect to the forward and backward parts of the heel. However for economies in manufacturing, the outer heel sacs (12 i and 12 s) and the inner heel sacs (13 i, 13 s) could be combined as shown in FIGS. 15 and 16 , into a single sac (30 i, 30 s) underlying the whole of the heel. This is not the preferred construction, but nevertheless provides the wearer with at least a major part of the necessary sensory information.

Similarly, the little toe sacs (17 i and 17 s) can be combined with the intermediate toe sacs (18 i, 18 s) to form a single sac (31 i, 31 s) which underlies all of the smaller toes i.e. underlies all of the toes except the big toe. This is not regarded as the optimum construction, but nevertheless provides the wearer with sufficient sensory feedback, and it is envisaged that this construction would be significantly cheaper to manufacture.

The outer heel sacs (12 i and 12 s), little toe sacs (17 i and 17 s), plus intermediate sacs (18 i, 18 s), or combined smaller toe sacs (31 i, 31 s), and big toe sacs (19 i and 19 s), contribute to the formation of the three foot arches. They achieve this by contributing surface area to the primary foundation sites (13 i and 13 s, 15 i and 15 s, and 16 i and 16 s) respectively. They also act as outer sensors that provide the wearer with sensory information to better identify the primary foundation sites, and readily detect shifts of weight bearing away from these sites.

The latter applies to the awareness of forward, backward, medial and lateral shifts in weight bearing away from the primary foundation sites. If appropriate, the muscles of the big toe and little toe can push these toes downward onto their respective sacs, which then press onto the floor. This enables these toes to act as blocks to forward orientated shifts in weight bearing away from their respective primary foundation bearing sites. In summary, without the incorporation of a triangular arrangement of sacs into the design of the footwear, the invention would not be able to teach the wearer the correct formation of the three foot arches and how to maintain them in relation to everyday body functions. Certainly, without this basic knowledge, the correct learning of more advanced body postures and balance skills would not be facilitated.

The majority of foot movements are derived from the ankle. The foot itself has a comparatively small range of three dimensional movements. The primary roles of the foot are to provide a multisite weight bearing platform that facilitates multidirectional foot sole movements. To accomplish this it has a dynamic complement of robustness and mouldability, to facilitate an entirety of body movements and functions. The flexibility of the insole and shoe (20 i and 20 s respectively) is intended to complement the fundamental postures and movements of the moldable weight bearing foot platform. This capability applies to all commonly utilised foot to floor contact interactions. For the shoe, the attached upper must also be suitably designed and structured to complement the moldability of the majority of the foot.

The wearer is made aware of correct foot and general body postures when his or her body weight is dynamically balanced over one or more sacs. Correct postures are the product of a systemic networking of body forces that act to correctly align all involved joints. Conversely, incorrect postures are the product of a systemic networking of body forces that act to misalign all involved joints. Accordingly, correct or incorrect balancing of the body over a sac or sacs corresponds to a respective correct or incorrect transfer of body forces across all involved joints. The body segments and respective joints most subject to this networking of alignment conforming forces are the lower limb, pelvis and lower spine.

With advanced training the wearer will be able to comprehend the basic anatomy of lower limb joints, in particular the shaping of their joint surfaces. This facilitates the wearer learning to perceive the movement and alignment interactions of these surfaces. From this knowledge the wearer learns to correlate the multidirectional rocker movements of sacs with the corresponding multidirectional movements of joint surfaces. With increasing skill the status of alignment of any particular joint becomes increasingly apparent to the wearer; for any given position or movement of the joint. A common component of joint misalignment is joint surface wedging. This causes the tissues on the wedge open side of the joint to tautly tension thereby resisting further wedging. The wearer learns to correlate this feeling of stretch and corresponding joint wedging with sac rolling for the shoe, and sac tilting for the insole.

Other forms of misalignments are screw and shear. These misalignments also cause restraining joint tissues to become taut and are accordingly amenable to detection by the wearer as a stretch of these tissues. The wearer is trained to register these stretch feelings as detrimental for the respective joints. The feeling of joint stretch is absent for correct joint alignment as joint tissues are insufficiently tensioned. This absence of stretch feeling should apply to the body postures associated with the loading of forefoot sacs in FIGS. 6 b, c and d for the insole, and FIGS. 14 b, c and d for the shoe.

The above learning process, in addition to a basic knowledge of anatomy, teaches the wearer to perceive joint alignments and respective joint surface couplings. For an inward roll movement of the ankle and foot, the most common indicator of joint misalignment is the feeling of tissue stretch on the medial side of the ankle. This ankle movement is depicted for the insole in FIG. 6 e , and for the shoe in FIG. 14 e . It is predisposed by a medial shift of body load to the extent that it becomes unbalanced on sac 16 i or 16 s, and as a consequence, the ankle and foot are forced to roll medially. The same movement acts to roll and bow the respective knee medially, which tautly tensions the tissues on the medial side of the knee. In contrast, when the wearer's body weight is balanced over a sac or sacs, as shown for the insole in FIGS. 6 b, 6 c and 6 d , and for the shoe in FIGS. 14 b, 14 c and 14 d , the ankle and knee are perceived to be correctly aligned.

The ability of the wearer to become familiar with the alignments of multiple joints facilitates their awareness of the concept of systemic interdependent joint alignments. This learning process would initially apply to the joints of the lower limbs, and then, with advanced training, extend to those of the pelvis and spine. This learning is very applicable when there is joint pain. The joint that becomes painful is commonly the one with the most significant misalignment within a networking of joint misalignments. Resolving the pain is facilitated by the correction or significant improvement of the alignment of the respective joint. Learning to perceive joint alignments in this systemic interdependent manner is also highly relevant to joint degeneration. As for symptomatic joints, the joint most predisposed to degeneration is commonly the most significantly misaligned. The accelerated degeneration of these joints can once again be markedly lessened by the correction or significant improvement of their alignments. All of this learning can be sourced from corresponding sac behaviours to foot sole loadings.

The easiest correct foot posture to learn is that used for regular standing. This foot posture can be referenced to be the most fundamental foot posture. This foot posture and corresponding sac loadings are shown in FIG. 5 for the insole and FIGS. 8 c and 13 for the shoe.

In these Figures, the wearer's body weight is spread to some extent across all of the sacs, providing the wearer with a wide base of support to more easily balance his or her body across the footwear. Sensory information from the majority of the foot sole is readily accessible to the wearer to inform him or her of load distribution across the sacs, and minute changes in this loading between the sacs. The primary indicator of correct foot posture for regular standing is when body load is centrally balanced over sacs 13 i, 15 i and 16 i for the insole and sacs 13 s, 15 s and 16 s for the shoe. These sacs are arranged in the shape of a triangle which corresponds to the orientation of the three foot arches. The centring of body load over these sacs is facilitated by subtle body segment manoeuvring in relation to the sacs. A component of this learning is to consider all first detectable biases of sac loadings to be outer range foot sole movements. An advance on this exercise is to apply the same load bias avoidance to the remaining sacs as they, to a lesser extent, are also loaded in regular standing. An earlier stage of this learning is to perform the same subtle changes in sac loadings whilst sitting.

There are three regular or fundamental correct forefoot postures. The footwear is designed to teach the wearer to become familiar with these postures. They primarily involve the medial and lateral forefoot sacs, sacs 16 i and 15 i for the insole and sacs 16 s and 15 s for the shoe. However the toe sacs 17 i and 19 i for the insole, and sacs 17 s and 19 s for the shoe, are integrally involved. The first posture involves the correct loading of both forefoot sacs as shown in FIGS. 6 b and 14 b . This is the forefoot loading commonly incorporated into the foot movement for relaxed walking. The second posture primarily involves the medial forefoot sac as shown in FIG. 6 c for the insole and FIG. 14 c for the shoe. For this posture the majority of weight bearing is localised to the forefoot medial sac (sac 16 i and 16 s). This is the forefoot loading for activities that necessitate a robust foot posture including sprinting, jumping and energetic stair climbing/descending. The third posture is the converse to the second posture. For the third posture the majority of forefoot weight bearing is localised to the lateral forefoot sac (sac 15 i and 15 s). This is the forefoot loading used for more everyday activities including lateral changes in the direction of the body when walking and for regular standing on the forefeet and toes when reaching up for an object.

The correct balancing of body load onto the toes is facilitated by the incorporation into the footwear of the three toe sacs (sacs 17 i, 18 i and 19 i for the insole, and sacs 17 s, 18 s and 19 s for the shoe). These sacs facilitate the correct transfer of body load onto one or more of the toes for respective body undertakings. A good example is raising the body to reach a high shelf. Correct balancing on the big toe and/or little toes, requires precision body balancing over a robust correctly postured foot, which is facilitated by these sacs.

The present footwear inventions have been found to be effective to markedly improve most sideways deviations in foot posture including pronation (rolling inward of the foot with a flattening of the medial longitudinal foot arch). These improvements require an advanced level of body posture and balance skill, that can be obtained by a progression of training using the footwear inventions.

The joints of the big toe are commonly found to be misaligned with associated deformities. The big toe sacs (sac 19 i and 19 s) reveal to the wearer the nature of these misalignments. The footwear cannot correct permanent deformities of the big toe joints, or any other joints, but it can make the wearer aware of the forces contributing to these deformities and subsequently how to significantly lessen these forces. The common cause of big toe deformities is foot pronation and associated lateral deviation of the big toe for the toe-off component of gait. In this instance, a significant correction of the pronation and corresponding improvement in big toe sac loading for toe-off, significantly lessens the forces acting to deviate the toe laterally.

Effectively, because the sacs lie under each of the primary weight bearing surfaces of the foot, they provide ideally located load sensory platforms for the wearer to quickly become aware of foot postures and changes in these postures in response to subtle changes in body segment positioning. When loaded, each sac behaves like a multidirectional balance platform so ensuring that the wearer must dynamically adjust his or her body posture to attain and maintain body balance over the respective sac or sacs. This necessitates the priority use of the centrally located chest, waist and pelvis segments, and is applicable to most commonly utilised forms of foot sole weight bearing. The direct correlation between body postures and the systemic interdependence of joint alignments facilitates the wearer's ongoing learning of the mechanics of his or her body. This educates the wearer to self correct joint misalignments and when applicable treat respective tissue pains; in addition to attain advance body balancing.

The standardised method to correct foot postures is to utilise prescription insoles. Prescription insoles correct foot and lower limb postures from the foot upwards, whereas the present inventions correct them principally from the central body downwards. The standardised method to treat localised pressure related foot pain is to utilise cushioning insole pads, usually made of a gel substance. These insoles accommodate the respective incorrect foot posture rather than attempt to correct it.

With increased learning, the improvements in foot and predisposing body postures obtained from using the footwear are increasingly retained when not using the footwear. The invention is intended to teach the wearer to become aware of correct foot and predisposing body postures and balance, in relation to fundamental foot sole weight bearing. The latter applies to the eight primary weight bearing sites of the foot sole. With advanced training the wearer can obtain a heightened awareness of correct systemic body posturing and balance that applies to multi-positional and multi-functional, static and dynamic, foot sole weight bearing. With ongoing training these skills increasingly operate at a subconscious level. Conscious involvements become more applicable to occurrences of significant postural perturbations, and feelings of tissue stretches and associated joint stiffness.

In most situations the full correction of foot posture and corresponding general body postures is not achievable due to the presence of permanent physical and/or neural damage such as joint deformities and post stroke. Full corrections are also negated by entrenched joint misalignments, and genetic factors such as an innate predisposition for pronating feet and hypermobility of joints. The footwear invention would not be appropriate in situations where the extent of disabling factors precluded the wearer's ability to attain an even spread of weight bearing across a majority of sacs.

The vast majority of individuals have entrenched postural factors that act to return their original postural traits. For this reason periodic ongoing training with the footwear is recommended. The regular conscious assessment of foot weight bearing and corresponding body postures when not wearing the footwear or using the insole, is also recommended. Another recommendation is the standard use of comfortable fitting shoes that accommodates the natural shape of the foot. The use of standard insoles is also recommended for everyday use because their shaping provides the trained wearer with heightened sensory cues concerning his or her foot sole loadings.

Training instruction material must be provided with each pair of shoes and insoles to ensure their beneficial usage. Incorrect usage, such as prioritising lower leg and foot muscles to lift the arch of the foot and prevent the foot from rolling inward, will result in detrimental lower limb, pelvis and spinal function. The wearer must therefore be fully aware that incorrect usage of the shoe or insole inventions will promote and possibly entrench detrimental posture and widespread body function.

The footwear sole of the present invention has been found effective in retraining a wearer's posture so that, after a course of training using the footwear sole has been completed, the wearer has markedly improved general body posture, but particularly that of the lower limbs, for all activities when wearing comfortable footwear or when barefoot. The improvements extend from physically demanding activities to resting non-weight-bearing states. The transference of posture and balance correction obtained from wearing the footwear inventions, to not wearing them, will to a large extent be determined by the wearer's motivation to advance his or her respective level of systemic body awareness and balance skill. 

1.-8. (canceled)
 9. A sole for footwear for a wearer's foot, wherein the wearer's foot has primary weight bearing surfaces with a full extent of convexities, and wherein the weight bearing surfaces include a heel, which includes an inner heel and an outer heel, a medial longitudinal arch, a lateral forefoot, a lateral midfoot, a big toe and smaller toes, which include a smallest toe and remaining small toes, said sole including: a plurality of separate closed fluid filled sacs flexibly secured together and arranged such that said plurality of separate closed fluid filled sacs are positioned under the full extent of convexities of the primary weight bearing surfaces of the wearer's foot, said plurality of separate closed fluid filled sacs being arranged such that no part of said plurality of separate closed fluid filled sacs is positioned under the medial longitudinal arch of the wearer's foot on said sole; at least one sac positioned under the wearer's heel on said sole; at least five sacs positioned under the wearer's foot other than the heel, wherein said at least five sacs include: a first sac positioned under the medial forefoot of the wearer's foot on said sole; a second sac positioned under the lateral forefoot of the wearer's foot on said sole; a third sac positioned under the lateral midfoot of the wearer's foot on said sole; a fourth sac positioned under the big toe of the wearer's foot on said sole; a fifth sac positioned under the smaller toes of the wearer's foot on said sole.
 10. The sole for footwear as claimed in claim 9, wherein said at least one sac positioned on said sole under the wearer's heel includes two separate independent sacs, one of which is positioned under the outer heel and another of which is positioned under the inner heel.
 11. The sole for footwear as claimed in claim 9, wherein said fifth sac is sub-divided into two separate independent sacs, one of which lies under the smallest toe and the other of which lies under the remaining small toes.
 12. The sole for footwear as claimed in claim 9, wherein the fluid filling said plurality of separate closed fluid filled sacs is air at at least ambient pressure.
 13. The sole for footwear as claimed in claim 9, wherein said plurality of separate closed fluid filled sacs are filled with liquid at at least ambient pressure.
 14. The sole for footwear as claimed in claim 9, wherein said sole is shaped to fit inside an article of footwear and each of said plurality of separate closed fluid filled sacs is substantially oval in cross-section.
 15. The sole for footwear as claimed in claim 9, wherein said sole is designed to be attached to the exterior surface of the underside of an article of footwear, and each of said plurality of separate closed fluid filled sacs is a slightly oval circle in cross-section.
 16. A sole for footwear having primary weight bearing surfaces, and wherein the weight bearing surfaces include a heel support surface, inclusive of an inner heel support surface and an outer heel support surface, a medial longitudinal arch support surface, a lateral forefoot support surface, a lateral midfoot support surface, a big toe support surface and smaller toes support surface, inclusive of a smallest toe support surface and remaining small toes support surface, said sole including: a plurality of separate closed fluid filled sacs flexibly secured together and arranged on said sole within said footwear, said plurality of separate closed fluid filled sacs being arranged such that no part of said plurality of separate closed fluid filled sacs is positioned within the medial longitudinal arch support surface; at least one sac positioned in the wearer's heel support surface; at least five sacs positioned on said sole in positions other than the heel support surface, wherein said at least five sacs include: a first sac positioned in the medial longitudinal arch support surface; a second sac positioned in the lateral forefoot support surface; a third sac positioned in the lateral midfoot support surface; a fourth sac positioned in the big toe support surface; and a fifth sac positioned in the smaller toes support surface.
 17. The sole as claimed in claim 16, wherein said at least one sac positioned in the wearer's heel support surface includes two separate independent sacs, one of which is positioned under the outer heel support surface and another of which is positioned under the inner heel support surface.
 18. The sole as claimed in claim 16, wherein said fifth sac is sub-divided into two separate independent sacs, one of which is in the smallest toe support surface and the other of which is in the remaining small toes support surface.
 19. The sole as claimed in claim 16, wherein the fluid filling said plurality of separate closed fluid filled sacs is air at at least ambient pressure.
 20. The sole as claimed in claim 16, wherein said plurality of separate closed fluid filled sacs are filled with liquid at at least ambient pressure.
 21. The sole for footwear as claimed in claim 16, wherein each of said plurality of separate closed fluid filled sacs is substantially oval in cross-section.
 22. A sole for footwear, wherein said sole has an underside on an exterior of the footwear, and wherein said sole has primary weight bearing surfaces, and wherein the weight bearing surfaces include a heel support surface, inclusive of an inner heel support surface and an outer heel support surface, a medial longitudinal arch support surface, a lateral forefoot support surface, a lateral midfoot support surface, a big toe support surface and smaller toes support surface, inclusive of a smallest toe support surface and remaining small toes support surface, said sole including: a plurality of separate closed fluid filled sacs flexibly secured together and arranged on said underside of said sole, said plurality of separate closed fluid filled sacs being arranged such that no part of said plurality of separate closed fluid filled sacs is positioned within the medial longitudinal arch support surface; at least one sac positioned in the wearer's heel support surface; at least five sacs positioned on said sole in positions other than the heel support surface, wherein said at least five sacs include: a first sac positioned in the medial longitudinal arch support surface; a second sac positioned in the lateral forefoot support surface; a third sac positioned in the lateral midfoot support surface; a fourth sac positioned in the big toe support surface; and a fifth sac positioned in the smaller toes support surface.
 23. The sole as claimed in claim 22, wherein said at least one sac positioned in the wearer's heel support surface includes two separate independent sacs, one of which is positioned under the outer heel support surface and another of which is positioned under the inner heel support surface.
 24. The sole as claimed in claim 22, wherein said fifth sac is sub-divided into two separate independent sacs, one of which is in the smallest toe support surface and the other of which is in the remaining small toes support surface.
 25. The sole as claimed in claim 22, wherein the fluid filling said plurality of separate closed fluid filled sacs is air at at least ambient pressure.
 26. The sole as claimed in claim 22, wherein said plurality of separate closed fluid filled sacs are filled with liquid at at least ambient pressure.
 27. The sole for footwear as claimed in claim 22, wherein each of said plurality of separate closed fluid filled sacs is substantially oval in cross-section. 